Human immunodeficiency virus (HIV)-1 infection is a leading cause of morbidity and mortality around the world, with many new infections occurring daily and the development of a safe and effective HIV vaccine is a critically important global health priority. An effective vaccine for HIV remains elusive and the development of an effective vaccine against HIV is the long-term solution to this problem. The success of the RV144 Thai HIV-1 efficacy trail showing 31 % of efficacy has given hope that indeed a protective HIV vaccine can be developed. The goal of this program is to generate novel vaccination approaches that enhance the quantity as well as quality of anti-viral cellular and humoral responses using CD40L as an adjuvant and MVA delta4 as a boosting vector. The overall objectives for this Core are to provide the required experimental animals and support services needed to facilitate the AIDS vaccine development studies proposed in projects 2 and 3. This will be accomplished by the following specific aims: 1. To select and provide male rhesus macaques from the Yerkes breeding colony suitable for the research aims of the macaque trials of the program project. 2. To provide exceptional animal care, veterinary care, and environmental enrichment. 3. To perform vaccine administrations to measure immunogenicity. 4. To perform sample collections including the collection of various tissue samples and secretions for in vitro studies. 5. To perform repeated rectal SHIV challenges on immunized and unimmunized control animals to test vaccine efficacy. 6. To perform periodic physical examinations and blood collections from the experimental animals. 7. To perform complete gross and histologic evaluation of any experimental animals that dies or sacrificed during the course of the study.